Citalopram is a well-known antidepressant drug that has now been on the market for some years and has the following structure:

It is a selective, centrally acting serotonin (5-hydroxytyptamine; 5-HT) reuptake inhibitor, accordingly having antidepressant activities. The antidepressant activity of the compound has been reported in several publications, eg. J. Hyttel, Prog. Neuro-Psychopharmacol. & Biol. Psychiat., 1982, 6, 277-295 and A. Gravem, Acta Psychiatr. Scand., 1987, 75, 478-486, and it is now marketed for the treatment of depression and panic disorders. The compound has further been disclosed to show effects in the treatment of dementia and cerebrovascular disorders, EP-A 474580.
Escitolopram and a method for its preparation are disclosed in U.S. Pat. No. 4,943,590. The stereo selectivity of citalopram, i.e. the 5-HT-reuptake inhibition in the S-enantiomer, and accordingly, the antidepressant effect of said enantiomer is also disclosed. S-citalopram is now in development as an antidepressant.
Studies have shown that patients suffering from neurotic disorders including anxiety disorders, especially generalised anxiety, and panic attacks, in particular in association with agoraphobia, have a quality of life impairment comparable with or greater than the disability found in patients with alcoholism, schizophrenia or personality disorders. Furthermore, current treatments are not always effective or cause unacceptable side effects.
Consequently, there is a need for alternative therapies useful in the treatment of neurotic disorders.
Escitalopram has now been found to show potent effects in models of neurotic disorders such as anxiolytic effect and prominent effect in the treatment of panic attacks and obsessive compulsive disorder.